The present invention pertains to tool drivers and holders for rotary tools, and more particularly, to a new and improved tool driver suitable for driving acetabular reamer cups and patella cutters and other surgical tools of any size which is easily cleaned and held and guided to rotate in true concentricity with the tool driver.
Patella cutters and acetabular reamer cups are surgical tools which are used in surgery for the insertion of artificial joints. Acetabular reamer cups are used to cut hemispherical cavities in pelvis bones for the insertion of artificial hip joints. Patella cutters are used to shape the underside of the patella or knee cap during knee replacement surgery. Patella cutters have a complex arrangement of precisely shaped cutting edges spirally arranged around an axis of rotation for cutting the patella. Acetabular reamer cups have a complex arrangement of cutting edges spirally arranged on a spherical surface around the axis of rotation of the cup. Both acetabular reamers and patella cutters perform better when rotated precisely about the axis around which these cutting edges are positioned by design. Additionally precise tolerances cannot be achieved without precise axial rotation as designed.
It is therefore highly desirable to provide a new and improved tool driver. It is also highly desirable to provide a new and improved tool driver which can be used with acetabular reamer cups, patella cutters and like rotary tools. It is also highly desirable to provide a new and improved tool driver by which rotary tools may be driven about the tool driver""s longitudinal axis with preciseness such that all of the cutting edges of the rotary tool function as designed.
Acetabular reamer cups also come in a full range of sizes. These sizes range from about 36 millimeters in diameter to about 72 millimeters in diameter. In the past, a specific tool driver could only be used with one or few of the sizes of available acetabular reamer cups. Thus, in any operating room there had to be several tool drivers for acetabular reamer cups. It is therefore also highly desirable to provide a new and improved tool driver by which acetabular reamer cups and patella cutters of all sizes can be driven.
Unique to some knee surgery and some hip operations is the utilization of milled bone, tissue and debris as filler to be placed between the artificial insert and the body to assist the healing process. Thus, acetabular reamer cups and patella cutters are mounted on tool drivers in a manner to collect such debris for such use. It is therefore, also highly desirable to provide a new and improved tool driver on which the rotary tools of the type which collect milled bone tissue and other debris for use as filler can be used.
In all surgery utilizing rotary tools, rotary tools such as those driven by rotary tool drivers must be separable from their tool drivers to replace or sharpen as required. It may also be necessary to change tools during an operation, thus, both the rotary tools and the tool drivers must at times be cleaned, sterilized and reused. Thus, it is therefore also highly desirable to provide a new and improved tool driver which can be easily cleaned, sterilized and reused.
Some previous tool drivers grip the tool utilizing opposed pins, flanges and slots, or opposed spring loaded ball catches, or other such devices. These devices represent a problem in that the catches tend to trap dried blood and other debris which are very difficult to remove during a cleaning process. It is therefore also highly desirable to provide a new and improved tool driver which is simple in construction, easy to use and does not have opposed pins, flanges, slots and other devices in which to catch debris and render the tool driver difficult to clean, sterilize and reuse.
An additional problem is that unless tolerances of tools and tool drivers are made very close, at a greatly increased cost, there is considerable free play between the tool and the tool driver. This increased play increases the wear of the cutting edges, makes more difficult the positioning of the tool, renders the tool useless for holding close tolerances, requires the tool not to cut as designed, and there is no possibility of utilizing the rotary tool spinning precisely about its axis as designed. It is therefore, also highly desirable to provide a new and improved tool driver which allows the rotary tool to be utilized spinning precisely about its axis, as designed.
It is also highly desirable to provide a new and improved tool driver in which close tolerances can be held.
Finally, it is highly desirable to provide a new and improved tool driver which has all of the above desired features.
It is therefore an object of the invention to provide a new and improved tool driver.
It is also an object of the invention to provide a new and improved patella driver which can be used with both acetabular cups, patella cutters and like rotary tools.
It is also an object of the invention to provide a new and improved tool driver by which rotary tools may be driven about the tool drivers longitudinal axis with preciseness such that all of the cutting edges of the rotary tool function as designed.
It is also an object of the invention to provide a new and improved tool driver which acetabular reamer cups of all sizes and patella cutters can be driven.
It is also an object of the invention to provide a new and improved tool driver on which the rotary tools of the type which collect milled bone tissue and other debris for use as filler, can be used.
It is also an object of the invention to provide a new and improved tool driver which can be easily cleaned, sterilized and reused.
It is also an object of the invention to provide a new and improved tool driver which allows the rotary tool to be utilized spinning precisely about its axis as designed.
It is also an object of the invention to provide a new and improved tool driver which is simple in construction, easy to use and does not have opposed pins, flanges, slots and other devices in which to catch debris and render the tool driver difficult to clean, sterilize and reuse.
It is also an object of the invention to provide a new and improved tool driver in which close tolerances can be held.
It is finally an object of the invention to provide a new and improved tool driver which has all of the above desired features.
In the broader aspects of the invention, there is provided a new and improved tool driver having a shaft with a longitudinal axis and opposite ends. A boss is secured at one of the shaft ends by which the tool driver is connected to a rotary tool. A tool collate is secured to the other of the shaft ends by which the tool driver may be driven by a surgical hand piece having a chuck in which the collate may be positioned. The boss is equipped with a securing device of the bayonet type having a latch mechanism which holds the rotary tool on the boss coaxially of the driver during use. In a specific embodiment, the securing device has a tapered bore extending from the distal end of the boss axially of the shaft. The rotary tool has a diametral bar extending across a bottom tool driver opening with a centrally located circular disk therein. The disk of the rotary tool fits within the bore of the tool shaft boss so as to concentrically locate the rotary tool and the tool shaft on the same axis. The latch mechanism holds the tool driver and the tool together in this position, whereby rotary tools of a multitude of sizes can be secured concentrically to the tool shaft without holding a plurality of critical tolerances when machining the bayonet type securing device or the rotary tool bottom bar.